For years, artificial restorative elements such as crowns, bridges, onlays, and inlays have been used in the field of dentistry. A crown is a single artificial tooth replica typically made of porcelain, or cast metal, or porcelain bonded to cast metal that is designed to fit over a tooth that has often been ground into the form of a stump. The crown has a similar configuration as the original tooth and is used as a restorative element. A bridge is composed of multiple crowns with artificial teeth interposed therebetween. In addition, onlays and inlays, or partial crowns, are used to restore portions of a tooth. For purposes of this application, the term "crown" will be used to represent all of the various types of crowns and bridges and onlays. The crown is bonded to the stump of the tooth using dental cement such as zinc phosphate cement or other bonding cements.
To ensure the longevity of the crown, it is very important that the crown is properly seated onto the tooth. Also, an improperly seated crown can compromise the marginal integrity of the crown. Decay can develop underneath the crown and the occlusion or bite may be off slightly causing the grinding down of the crown. Typically, the crown is placed over the tooth and the patient applies biting pressure on an object to force the crown into place. The biting pressure is applied while the dental cement hardens and a bond between the crown and tooth is formed. In the prior art, patients have applied biting pressure to an orangewood stick during the cementation of the crown. However, it has been found that the use of an orangewood stick may result in the cracking or chipping of the porcelain crown, necessitating the time and expense of manufacturing and reseating a new crown. Furthermore, the load applied to the crown with the use of the orangewood stick is uneven and can result in a crown that is improperly seated. Other prior art techniques include applying biting pressure to a rubber bite block such as that shown in U.S. Pat. No. 4,975,053 where the biting pressure is applied across the entire width of the tooth to be crowned. However, these prior art devices have similar shortcomings as discussed below, in that they fail to provide a device that allows for the uniform loading of the central groove of the tooth to be crowned, without also loading the lingual or buccal cusps of the crown.